WALDEN, H. Wzory do Obliczeń Przepływu Gazu w Nachylonych Gazociągach. Engineering Transactions, [S. l.], v. 9, n. 4, p. 601–608, 1961. Disponível em: http://et.ippt.gov.pl/index.php/et/article/view/2900. Acesso em: 17 jan. 2026.